bacfire and leaky carb

[dirtrider77]

ok so my 450 has been ported and polished, bored .40 over
and a weisco 13:1 piston, hmf exhaust, k&n...im running pump gas


when i am riding and let off the throttle it makes alot of popping noises from the exhaust....i tried to turn my fuel/air screw out a bit but if i turn it more than 1/4 of the way out, fuel starts coming out the overflow??

any tips??

thanks

[wckedclownz69]

might want to try using race gas... and how do you have your jetting set up.. thats a main factor too..

[dirtrider77]

k as far as the gas what would you recommend??

and i have no idea about the jets, havent took carb apart


any idea about the overflowing carb??

and if i used race gas and it doesnt help will i be able to go back?

thanks

[wckedclownz69]

well first i would get a jet kit if you don't already have one and as of gas you can use like a gallon of 108 106 and mix with 4 gallons of 93 or how ever much you use and jets would be the first to try and your getting too much gas in bowl if its coming out of overflow.. can be floats too all depends first check your main jet the numbers on it..

[dirtrider77]

k i will get a kit and check numbers and post em tomorrow

also, i can get the gas tomorrow but if it doesnt solve problem can i go back to reg. pump gas?

[wckedclownz69]

hmm with it bored and that size piston i dont think so.. but someone else knows more then me so they will post by tomorrow day-night

[Scro]

You are probably not turning the air/fuel screw, but rather the float drain screw. The air/fuel is on the bottom of the carb, the float drain is on the side.

I could help more if I knew what size jets you have in.

[dirtrider77]

and scro you are a very helpful guy, cause i was turning the screw on the side! so im going to go adjust the fuel/air screw then if no sucess i will come back and post my jet sizes